US20120099694A1 - Fast reactor - Google Patents
Fast reactor Download PDFInfo
- Publication number
- US20120099694A1 US20120099694A1 US13/266,489 US201013266489A US2012099694A1 US 20120099694 A1 US20120099694 A1 US 20120099694A1 US 201013266489 A US201013266489 A US 201013266489A US 2012099694 A1 US2012099694 A1 US 2012099694A1
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- United States
- Prior art keywords
- coolant
- pump
- core
- upper header
- header
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- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C1/00—Reactor types
- G21C1/32—Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core
- G21C1/322—Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core wherein the heat exchanger is disposed above the core
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- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C1/00—Reactor types
- G21C1/02—Fast fission reactors, i.e. reactors not using a moderator ; Metal cooled reactors; Fast breeders
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- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C15/00—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
- G21C15/02—Arrangements or disposition of passages in which heat is transferred to the coolant; Coolant flow control devices
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- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C15/00—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
- G21C15/24—Promoting flow of the coolant
- G21C15/243—Promoting flow of the coolant for liquids
- G21C15/247—Promoting flow of the coolant for liquids for liquid metals
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- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C11/00—Shielding structurally associated with the reactor
- G21C11/02—Biological shielding ; Neutron or gamma shielding
- G21C11/022—Biological shielding ; Neutron or gamma shielding inside the reactor vessel
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Definitions
- the present invention relates to a fast reactor, in particular, a fast reactor having a high coolant sealing property and an excellent maintainability.
- Patent Document 1 shows an example of a conventional fast reactor, which is shown in FIG. 15 .
- the fast reactor 1 described in Patent Document 1 includes a core 2 formed of a nuclear fuel assembly.
- the core 2 has a substantially cylindrical shape as a whole.
- An outer circumference of the core 2 is surrounded by a core barrel 3 .
- a reflector 4 surrounding the core barrel 3 is located outside the core barrel 3 .
- Outside the reflector 4 there is disposed a bulkhead 6 that surrounds the reflector 4 and constitutes an inner wall of a flow path through which a primary coolant 21 (coolant) flows.
- a reactor vessel 7 constituting an outer wall of the flow path of the primary coolant 21 is located outside the bulkhead 6 , with a predetermined clearance therebetween.
- a neutron shield 8 is disposed in the flow path of the primary coolant 21 such that the neutron shield 8 surrounds the core 2 .
- the core 2 , the core barrel 3 , the bulkhead 6 and the neutron shield 8 are respectively supported by a core support 13 from below.
- the primary coolant 21 passes through the neutron shield 8 and the core supports 13 and then reaches the core 2 , whereby the cored 2 is cooled.
- the primary coolant 21 heated by the core 2 while passing therethrough is sent to an intermediate heat exchanger 15 .
- the intermediate heat exchanger 15 the heat is exchanged between the primary coolant 21 and a secondary coolant 31 .
- the intermediate heat exchanger 15 is configured to be drawn from the reactor vessel 7 .
- a seal bellows attached to the intermediate heat exchanger is seated on a bellows seat fixed on the bulkhead 6 .
- the seal bellows is compressed by a weight of the intermediate heat exchanger 15 .
- a temperature of the primary coolant 21 in a zone (higher temperature zone) from an outlet of the core 2 to an inlet of the intermediate heat exchanger 15 is about 500° C.
- a temperature of the primary coolant 21 in a zone (lower temperature zone) from an outlet of the intermediate heat exchanger 15 to an inlet of the core 2 is about 350° C.
- the structural member supporting the core 2 is used under such conditions as a high temperature and a large temperature difference.
- the bulkhead 6 constituting the inner wall of the flow path of the primary coolant 21 also experiences a large pressure difference between the higher temperature zone and the lower temperature zone, in addition to the above temperature difference, the bulkhead 6 is exposed to an extremely severe environment.
- the intermediate heat exchanger 15 and the electromagnetic pump 14 are arranged in series with each other.
- the electromagnetic pump 14 having a higher failure probability is damaged, the electromagnetic pump 14 and the intermediate heat exchanger 15 should be simultaneously pulled out.
- these equipments are radioactivated, it is necessary to exchange both of the equipments.
- a huge cask for storing these equipments or for bringing these equipments to a disposal place is needed, an enormous cost is required.
- the present invention has been made in view of the above circumstances.
- the object of the present invention is to provide a fast reactor having a high primary coolant sealing property and an excellent maintainability.
- a fast reactor comprises:
- a reactor vessel accommodating therein a core and a coolant
- a core supporting mechanism disposed in the reactor, the core supporting mechanism extending horizontally so as to support the core;
- a bulkhead extending in parallel with the core and surrounding the core from a lateral side;
- an intermediate heat exchanger disposed between an inner surface of the reactor vessel and the bulkhead, the intermediate heat exchanger being configured to cool the coolant that has been heated by the core;
- a pump for coolant disposed between the inner surface of the reactor vessel and the bulkhead, the pump for coolant being configured to pressurize the coolant that has passed through the intermediate heat exchanger so as to be cooled;
- a lower plenum structured below the core supporting mechanism, the lower plenum being configured to guide the coolant which has been pressurized by the pump for coolant to the core;
- the core supporting mechanism is provided with an opening through which the pressurized coolant from the pump for coolant passes;
- a coolant guide mechanism configured to guide the pressurized coolant from the pump for coolant to the lower plenum through the opening of the core supporting mechanism.
- the fast reactor according to the present invention may further comprise a neutron shield located below the pump for coolant,
- the core supporting mechanism is formed of an upper supporting plate disposed between the pump for coolant and the neutron shield so as to support the neutron shield, the upper support plate having an opening to which the coolant guide mechanism is connected.
- the coolant guide mechanism may include an upper header mounted on the outlet of the pump for coolant, and a lower header disposed below the upper header and mounted on the upper supporting plate, the upper header may be provided with a downwardly projecting nozzle through which the pressurized coolant from the pump for coolant passes, and the lower header may be provided with a nozzle receiver slidably engaged with the nozzle of the upper header.
- the coolant guide mechanism may include an annular upper header mounted on the outlet of the pump for coolant, and an annular lower header disposed below the upper header and mounted on the upper supporting plate
- the upper header may include an annular inner wall extending downwardly from the outlet of the pump for coolant and an annular outer wall extending downwardly from the outlet of the pump for coolant
- the lower header may include an annular receiving part slidably engaged with the inner wall of the upper header and the outer wall of the upper header.
- the core supporting mechanism may be formed of a core support supporting the core from below and having an opening to which the coolant guide mechanism is connected.
- the coolant guide mechanism may include an upper header mounted on the outlet of the pump for coolant, and a lower header disposed below the upper header and mounted on the core support, and the upper header may be provided with a downwardly projecting nozzle through which the pressurized coolant from the pump for coolant passes, and the lower header may be provided with a nozzle receiver slidably engaged with the nozzle of the upper header.
- the coolant guide mechanism may include an annular upper header mounted on the outlet of the pump for coolant, and an annular lower header disposed below the upper header and mounted on the core support, the upper header may include an annular inner wall extending downwardly from the outlet of the pump for coolant and an annular outer wall extending downwardly from the outlet of the pump for coolant, and the lower header may include an annular receiving part slidably engaged with the inner wall of the upper header and the outer wall of the upper header.
- the fast reactor according to the present invention may further comprise:
- a neutron shield located below the pump for coolant
- an upper supporting plate disposed between the pump for coolant and the neutron shield so as to support the neutron shield
- the coolant guide mechanism includes an upper header mounted on the outlet of the pump for coolant, and a pipe passing through the upper supporting plate with one end of the pipe being engaged with the upper header and the other end thereof being connected to the core support;
- the upper header is provided with a downwardly projecting nozzle through which the pressurized coolant from the pump for coolant passes;
- the one end of the pipe is slidably engaged with the nozzle of the upper header.
- the nozzle may be connected to the upper header through a spherical seating seal.
- the upper header may be provided with a plurality of nozzles, and at least one of the nozzles is longer than the other nozzle(s).
- the pump for coolant when seen from above, may be arranged on a position nearer to the core than the intermediate heat exchanger, such that the pump for coolant and the intermediate heat exchanger do not overlap with each other.
- a part of the bulkhead, which is located above the upper supporting plate, may be formed of a manometerseal.
- the pump for coolant which is configured to pressurize the coolant that has passed through an intermediate heat exchanger so as to be cooled, is disposed between the inner surface of the reactor vessel and the bulkhead, and the neutron shield is disposed below the pump for coolant.
- the upper supporting plate supporting the neutron shield is disposed between the pump for coolant and the neutron shield.
- the upper supporting plate has the opening through which the pressurized coolant from the pump for coolant passes.
- the coolant guide mechanism Disposed between the outlet of the pump for coolant and the upper supporting plate is the coolant guide mechanism configured to guide the pressurized coolant from the pump for coolant toward the neutron shield through the opening of the upper supporting plate.
- the coolant of a lower temperature which has been cooled by the intermediate heat exchanger and pressurized by the pump for coolant, can be guided by the coolant guide mechanism toward the neutron shield through the opening of the upper supporting plate. Therefore, there is no possibility that the coolant of a lower temperature, which has been pressurized by the pump for coolant, leaks to the coolant of a higher temperature, which has been heated by the core, through the bulkhead, whereby it is possible to improve a sealing property between the coolant of a lower temperature, which has been pressurized by the pump for coolant, and the coolant of a higher temperature, which has been heated by the core. As a result, lowering of a power generation efficiency of the fast reactor can be prevented, as well as reliability of the fast reactor can be enhanced.
- FIG. 1 is a view showing a fast reactor in a first embodiment of the present invention.
- FIG. 2 is a view showing a sealing structure around an electromagnetic pump in the first embodiment of the present invention.
- FIG. 3 is a view showing a coolant guide mechanism in the first embodiment of the present invention.
- FIG. 4( a ) is a view showing an upper header when seen from above in the first embodiment of the present invention.
- FIG. 4( b ) is a view showing the upper header when seen from below in the first embodiment of the present invention.
- FIG. 4( c ) is a view showing a nozzle of the upper header in enlargement.
- FIG. 5( a ) is a view showing a lower header when seen from above in the first embodiment of the present invention.
- FIG. 5( b ) is a view showing the lower header when seen from below in the first embodiment of the present invention.
- FIG. 6( a ) is a view showing that the upper header and the lower header are connected to each other in the first embodiment of the present invention.
- FIG. 6( b ) is a sectional view showing that the upper header and the lower header are connected to each other in the first embodiment of the present invention.
- FIG. 7 is a view showing a coolant guide mechanism in a second embodiment of the present invention.
- FIG. 8 is a view showing a coolant guide mechanism in a third embodiment of the present invention.
- FIG. 9 is a view showing a coolant guide mechanism in a fourth embodiment of the present invention.
- FIG. 10 is a view showing a sealing structure around an electromagnetic pump in a fifth embodiment of the present invention.
- FIG. 11 is a view showing a fast reactor in a sixth embodiment of the present invention.
- FIG. 12 is a view showing a fast reactor in a seventh embodiment of the present invention.
- FIG. 13 is a view showing a fast reactor in an eighth embodiment of the present invention.
- FIG. 14 is a view showing a fast reactor in a ninth embodiment of the present invention.
- FIG. 15 is a view showing a conventional fast reactor.
- FIG. 1 to 6 are views showing a fast reactor in the first embodiment of the present invention.
- a fast reactor 1 in this embodiment is generally described with reference to FIG. 1 .
- the fast reactor 1 includes: a reactor vessel 7 accommodating there in a core 2 formed of a nuclear fuel assembly containing plutonium, and a primary coolant (coolant) 21 formed of liquid sodium; a core support 13 disposed in the reactor vessel 7 so as to support the core 2 from below; a core barrel 3 disposed on the core support 13 so as to surround the core 2 from a lateral side; a reflector 4 disposed so as to surround the core barrel 3 ; and an upwardly extending bulkhead 6 disposed on the core support 13 so as to surround the core 2 , the core barrel 3 and the reflector 4 from the lateral side.
- the reflector 4 is composed of a neutron reflecting part 4 a and a hollow cavity part 4 b . An inert gas or a metal having a lower neutron reflection ability than that of the primary coolant 21 is enclosed in the hollow space of the cavity part 4 b.
- annular intermediate heat exchanger 15 configured to cool the primary coolant 21 which has been heated by the core 2 .
- a pump for coolant e.g., an annular electromagnetic pump 14 configured to pressurize the primary coolant 21 that has passed through the intermediate heat exchanger 15 so as to be cooled is disposed between the inner surface of the reactor vessel 7 and the bulkhead 6 at a position near to the intermediate heat exchanger 15 .
- a neutron shield 8 is disposed between the inner surface of the reactor vessel 7 and the bulkhead 6 at a position below the electromagnetic pump 14 . As shown in FIG. 1 , disposed between the neutron shield 8 and the electromagnetic pump 14 is an upper supporting plate 29 supporting the neutron shield 8 from above.
- the bulkhead 6 is composed of a lower bulkhead 6 a surrounding the core 2 , core barrel 3 and the reflector 4 from the lateral side, and an upper bulkhead 6 b surrounding the primary coolant 21 which has been heated by the core 2 .
- the lower bulkhead 6 a is mounted on the upper supporting plate 29 through a sealing member (not shown), such that the lower bulkhead 6 a is slidable in an up and down direction.
- a sealing member not shown
- the upper supporting plate 29 has an opening 29 a through which the pressurized primary coolant 21 from the electromagnetic pump 14 passes.
- a coolant guide mechanism 17 configured to guide the pressurized primary coolant 21 from the electromagnetic pump 14 toward the neutron shield 8 through the opening 29 a of the upper supporting plate 29 .
- the primary coolant 21 guided toward the neutron shield 8 passes through an opening 13 a of the core support 13 to flow into a lower plenum 33 shown in FIG. 2 . Thereafter, the primary coolant 21 moves upward while cooling the core 2 .
- the primary coolant 21 which has been heated by the core 2 reaches an upper plenum 32 shown in FIG. 1 , and then flows into an inlet 15 a of the intermediate heat exchanger 15 over the upper bulkhead 6 b .
- the primary coolant 21 outflows from an outlet 15 b of the intermediate heat exchanger 15 . Then, the primary coolant 21 is sucked into an inlet 14 a of the inlet 14 a of the electromagnetic pump 14 .
- a zone filled with the primary coolant 21 which has been cooled by the intermediate heat exchanger 15 and is not yet pressurized by the electromagnetic pump 14 , provides a lower temperature and lower pressure zone 23 .
- a zone filled with the primary coolant 21 which has been pressurized by the electromagnetic pump 14 and is not yet heated by the core 2 , provides a lower temperature and higher pressure zone 24 .
- a zone filled with the primary coolant 21 which has been heated by the core 2 and is not yet cooled by the intermediate heat exchanger 15 , provides a higher temperature zone 25 .
- the annular electromagnetic pump 14 when seen from above, the annular electromagnetic pump 14 is arranged on a position nearer to the core 2 than the intermediate heat exchanger 15 , such that the annular electromagnetic pump 14 and the annular intermediate heat exchanger 15 do not overlap with each other.
- the electromagnetic pump 14 can be independently pulled out upward, while the intermediate heat exchanger 15 remains in the fast reactor 1 .
- the electromagnetic pump 14 since a failure rate of the electromagnetic pump 14 is higher than a failure rate of the intermediate heat exchanger 15 , the electromagnetic pump 14 should be more frequently replaced. At this time, suppose that the intermediate heat exchanger 15 and the electromagnetic pump 14 are arranged to be overlapped with each other, when seen from above. Under such a structure, when the broken electromagnetic pump 14 is replaced, the electromagnetic pump 14 is pulled out together with the intermediate heat exchanger 15 . In this case, since the electromagnetic pump 14 and the intermediate heat exchanger 15 are both radioactivated, not only the broken electromagnetic pump 14 but also the intermediate heat exchanger 15 , which is not broken, should be replaced.
- the annular electromagnetic pump 14 when seen from above, is arranged on a position nearer to the core 2 than the intermediate heat exchanger 15 , such that the annular electromagnetic pump 14 and the annular intermediate heat exchanger 15 do not overlap with each other.
- the intermediate heat exchanger 15 and the electromagnetic pump 14 when seen from above, costs required for maintaining the fast reactor 1 can be reduced.
- a part of the upper bulkhead 6 b of the bulkhead 6 which is located above the upper supporting plate 29 , a part of the upper bulkhead 6 b , which is located near to the electromagnetic pump 14 at a position nearer to the core 2 than the electromagnetic pump 14 , and a part of the upper bulkhead 6 b , which is located near to the electromagnetic pump 14 between the electromagnetic pump 14 and the intermediate heat exchanger 15 , are respectively formed of manometerseals 34 .
- manometer seals 34 Due to these manometer seals 34 , at the position near to the electromagnetic pump 14 , it can be securely prevented that the primary coolant 21 in the lower temperature and lower pressure zone 23 leaks to the higher temperature zone 25 , and that the primary coolant 21 in the higher temperature zone 25 leaks to the lower temperature and lower pressure zone 23 .
- the respective manometerseals 34 are filled with an inert gas 35 , whereby the heat can be prevented from moving from the higher temperature zone 25 to the lower temperature and lower pressure zone 23 .
- the coolant guide mechanism 17 is composed of an annular upper header 18 mounted on the outlet 14 b of the electromagnetic pump 14 , and an annular lower header 20 disposed below the upper header 18 such that the lower header 20 is mounted on the upper supporting plate 29 so as to cover an opening 29 a of the upper supporting plate 29 from above.
- the upper header 18 is provided with a plurality of nozzles 19 in a circumferential direction thereof. Each of the nozzles 19 projects downward and passes therethrough the pressurized primary coolant 21 from the electromagnetic pump 14 .
- the lower header 20 is provided with a plurality of nozzle receivers 20 a which are slidably engaged with the corresponding nozzles 19 of the upper header 18 .
- the pressurized primary coolant 21 from the electromagnetic pump 14 can be guided toward the neutron shield 8 through the opening 29 a of the upper supporting plate 29 , with the pressurized primary coolant 21 from the electromagnetic pump 14 being shielded from the primary coolant 21 in the lower temperature and lower pressure zone 23 .
- annular seals 19 a are interposed between the nozzles 19 and the nozzle receivers 20 a .
- a sealing member 51 is interposed between a lower surface of the lower header 20 and an upper surface of the upper supporting plate 29 .
- At least one of the nozzles 19 of the upper header 18 may be formed by a longer nozzle 19 c which is longer than the other nozzles 19 .
- the primary coolant 21 which had been heated by the core 2 , e.g., the primary coolant 21 of a temperature of about 500° C.
- the primary coolant 21 flows into the inlet 15 a of the intermediate heat exchanger 15 over the upper bulkhead 6 b .
- the intermediate heat exchanger 15 the heat is exchanged between the primary coolant 21 and a secondary coolant 31 shown in FIG. 1 , whereby the primary coolant 21 is cooled and the secondary coolant 31 is heated.
- the temperature of the primary coolant 21 which has been cooled in the intermediate heat exchanger 15 , is about 350° C., for example.
- the primary coolant 21 which has been cooled in the intermediate heat exchanger 15 , outflows from the outlet 15 b of the intermediate heat exchanger 15 . Then, the primary coolant 21 is sucked into the inlet 14 a of the electromagnetic pump 14 . The primary coolant 21 having been sucked into the inlet 14 a of the electromagnetic pump 14 is pressurized at the electromagnetic pump 14 . Thereafter, the primary coolant 21 is discharged from the outlet 14 b of the electromagnetic pump 14 . The primary coolant 21 having been discharged from the outlet 14 b of the electromagnetic pump 14 is guided toward the neutron shield 8 through the coolant guide mechanism 17 and the opening 29 a of the upper supporting plate 29 .
- the primary coolant 21 having been guided toward the neutron shield 8 then flows into the lower plenum 33 shown in FIGS. 1 and 2 through the opening 13 a of the core support 13 . After that, as shown in FIGS. 1 and 2 , the primary coolant 21 moves upward while cooling the core 2 .
- the primary coolant 21 having been discharged from the outlet 14 b of the electromagnetic pump 14 is guided by the coolant guide mechanism 17 toward the neutron shield 8 through the opening 29 a of the upper supporting plate 29 .
- the lower temperature and lower pressure zone 23 that is filled with the primary coolant 21 of about 350° C., which is not yet pressurized.
- the lower temperature and lower pressure zone 23 is in contact with the higher temperature zone 25 , which is filled with the primary coolant 21 of about 500° C. that has been heated by the core 2 , through the upper bulkhead 6 b .
- the lower temperature and higher pressure zone 24 which is filled with the pressurized primary coolant 21 of about 350° C., is not in contact with the higher temperature zone 25 , which is filled with the primary coolant 21 of about 500° C. that has been heated by the core 2 , through the upper bulkhead 6 b .
- the pressurized primary coolant 21 of about 350° C. leaks to the higher temperature zone 25 , and that a pressure difference between the lower temperature and higher pressure zone 24 and the higher temperature zone 25 is applied to the upper bulkhead 6 b .
- lowering of a power generation efficiency of the fast reactor 1 can be prevented, as well as reliability of the fast reactor 1 can be enhanced.
- the higher temperature zone 25 and the lower temperature and lower pressure zone 23 are in contact with each other through the upper bulkhead 6 b .
- a pressure difference between the higher temperature zone 25 and the lower temperature and lower pressure zone 23 which is about several Kpa, is substantially equal to a pressure loss in the intermediate heat exchanger 15 .
- a difference in height between a liquid level 34 a in the higher temperature zone 25 and a liquid level 34 b in the lower temperature and lower pressure zone 23 is about several hundreds mm.
- leakage of the primary coolant 21 between the higher temperature zone 25 and the zone 23 of a lower temperature and a lower temperature can be substantially made zero.
- the coolant guide mechanism 17 configured to guide the pressurized primary coolant 21 from the electromagnetic pump 14 toward the neutron shield 8 through the opening 29 a of the upper supporting plate 29 .
- the primary coolant 21 of a lower temperature which has been cooled by the intermediate heat exchanger 15 and pressurized by the electromagnetic pump 14 , can be guided by the coolant guide mechanism 17 toward the neutron shield 8 through the opening 29 a of the upper supporting plate 29 .
- the coolant guide mechanism 17 is composed of the annular upper header 18 mounted on the outlet 14 b of the electromagnetic pump 14 , and the annular lower header 20 disposed below the upper header 18 such that the lower header 20 is mounted on the upper supporting plate 29 so as to cover the opening 29 a of the upper supporting plate 29 from above.
- the upper header 18 is provided with a plurality of nozzles 19 in a circumferential direction thereof. Each of the nozzles 19 projects downward and passes therethrough the pressurized primary coolant 21 from the electromagnetic pump 14 .
- the lower header 20 is provided with a plurality of nozzle receivers 20 a which are slidably engaged with the corresponding nozzles 19 of the upper header 18 .
- the two annular seals 19 a are interposed between the nozzles 19 and the nozzle receivers 20 a .
- the pressurized primary coolant 21 from the electromagnetic pump 14 leaks to the lower temperature and lower pressure zone 23 , which is filled with the primary coolant 21 that is not yet pressurized.
- the annular electromagnetic pump 14 when seen from above, is arranged on a position nearer to the core 2 than the intermediate heat exchanger 15 , such that the annular electromagnetic pump 14 and the annular intermediate heat exchanger 15 do not overlap with each other.
- the electromagnetic pump 14 when the fast reactor 1 is repaired or maintained, the electromagnetic pump 14 can be independently pulled out upward, while the intermediate heat exchanger 15 remains in the fast reactor 1 .
- costs required for maintaining the fast reactor 1 can be reduced.
- a part of the upper bulkhead 6 b which is located near to the electromagnetic pump 14 at a position nearer to the core 2 than the electromagnetic pump 14
- a part of the upper bulkhead 6 b which is located near to the electromagnetic pump 14 between the electromagnetic pump 14 and the intermediate heat exchanger 15
- the manometerseals 34 Due to these manometerseals 34 , at the position near to the electromagnetic pump 14 , it can be securely prevented that the primary coolant 21 in the lower temperature and lower pressure zone 23 leaks to the higher temperature zone 25 , and that the primary coolant 21 in the higher temperature zone 25 leaks to the lower temperature and lower pressure zone 23 .
- the respective manometerseals 34 are filled with the inert gas 35 , whereby the heat can be prevented from moving from the higher temperature zone 25 to the lower temperature and lower pressure zone 23 .
- the pump for coolant is formed of the electromagnetic pump 14 , which is by way of example.
- a mechanical pump or another pump may be used as the pump for coolant.
- the annular intermediate heat exchanger 15 and the annular electromagnetic pump 14 are provided, which is by way of example.
- a plurality of intermediate heat exchangers 15 and a plurality of electromagnetic pumps 14 may be circumferentially arranged. In this case, the electromagnetic pump 14 can be pulled out upward more easily.
- a part of the upper bulkhead 6 b which is located near to the electromagnetic pump 14 at a position nearer to the core 2 than the electromagnetic pump 14
- a part of the upper bulkhead 6 b which is located near to the electromagnetic pump 14 between the electromagnetic pump 14 and the intermediate heat exchanger 15
- the manometerseal 34 may be used only on one of a part which is located near to the electromagnetic pump 14 at a position nearer to the core 2 than the electromagnetic pump 14 , and a part which is located near to the electromagnetic pump 14 between the electromagnetic pump 14 and the intermediate heat exchanger 15 .
- the upper header 18 may be placed below the flowmeter.
- FIG. 7 is a view showing a coolant guide mechanism in the second embodiment of the present invention.
- the second embodiment shown in FIG. 7 is substantially the same as the first embodiment shown in FIGS. 1 to 6 , excluding that respective nozzles are connected to an upper header through spherical seating seals.
- the same elements as those of the first embodiment shown in FIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted.
- respective nozzles 19 of a coolant guide mechanism 17 are connected to an upper header 18 through spherical seating seals 19 b .
- each nozzle 19 can be optionally inclined within a predetermined range with respect to the upper header 18 . Therefore, a manufacturing tolerance and an installation tolerance of the coolant guide mechanism 17 can be absorbed, as well as a structural deformation of the coolant guide mechanism 17 , which is caused during the operation of a fast reactor 1 , can be absorbed.
- alignment of each nozzle 19 with a corresponding nozzle receiver 20 a of a lower header 20 can be facilitated.
- the respective nozzles 19 of the coolant guide mechanism 17 are connected to the upper header 18 through the spherical seating seals 19 b .
- the pressurized primary coolant 21 from the electromagnetic pump 14 leaks to the lower temperature and lower pressure zone 23 , which is filled with the primary coolant 21 that is not yet pressurized.
- installation of the fast reactor 1 can be facilitated, and maintainability of the fast reactor 1 can be enhanced.
- FIG. 8 is a view showing a coolant guide mechanism in the third embodiment of the present invention.
- the third embodiment shown in FIG. 8 is substantially the same as the first embodiment shown in FIGS. 1 to 6 , excluding that the coolant guide mechanism includes a pipe passing through an upper supporting plate, with one end of the pipe being engaged with an upper header, and the other end thereof being connected to a core support.
- the same elements as those of the first embodiment shown in FIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted.
- a coolant guide mechanism 17 includes an annular upper header 18 mounted on an outlet 14 b of an electromagnetic pump 14 , and a pipe 22 passing through an upper supporting plate 29 , with one end 22 a of the pipe 22 being engaged with the upper header 18 and the other end 22 b of the pipe 22 being connected to a core support 13 .
- the upper header 18 is provided with downwardly projecting nozzles 19 through which a pressurized primary coolant 21 from the electromagnetic pump 14 passes.
- the one end 22 a of the pipe is slidably engaged with the nozzles of the upper header 18 through two annular seals 19 a.
- the pipe 22 passing through the upper supporting plate 29 with the one end 22 a being slidably engaged with the upper header and the other end 22 b being connected to the core support 13 . Since the outlet 14 b of the electromagnetic pump 14 and the upper supporting plate 29 are connected to each other through the pipe 22 , the primary coolant 21 can be guided up to a lower plenum 33 without diminishing its flow rate. Thus, the efficiency of a fast reactor 1 can be enhanced, as well as the sealing structure between the upper supporting plate 29 and the core barrel 3 can be facilitated.
- FIG. 9 is a view showing a coolant guide mechanism in the fourth embodiment of the present invention.
- the fourth embodiment shown in FIG. 9 is substantially the same as the first embodiment shown in FIGS. 1 to 6 , excluding that an upper header includes an annular inner wall extending downwardly from an outlet of an electromagnetic pump and an annular outer wall extending downwardly from the outlet of the electromagnetic pump, and that a lower header includes an annular receiving part slidably engaged with the inner wall of the upper header and the upper wall thereof.
- the same elements as those of the first embodiment shown in FIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted.
- a coolant guide mechanism 17 is composed of an annular upper header 18 mounted on an outlet 14 b of an electromagnetic pump 14 , and an annular lower header 20 disposed below the upper header 18 such that the lower header 20 is mounted on an upper supporting plate 29 so as to cover an opening 29 a of the upper supporting plate 29 from above.
- the upper header 18 includes an annular inner wall 18 a extending downwardly from the outlet 14 b of the electromagnetic pump 14 , and an annular outer wall 18 b extending downwardly from the outlet 14 b of the electromagnetic pump 14 .
- formed on the lower header 20 is an annular receiving part 20 b slidably engaged with the inner wall 18 a of the upper header 18 and the outer wall 18 b thereof.
- Two annular seals 19 d are interposed between the annular inner wall 18 a and an inner side surface of the annular receiving part 20 b .
- Two annular seals 19 e are interposed between the annular outer wall 18 b and an outer side surface of the annular receiving part 20 b.
- the upper header 18 includes the annular inner wall 18 a extending downwardly from the outlet 14 b of the electromagnetic pump 14 , and the annular outer wall 18 b extending downwardly from the outlet 14 b of the electromagnetic pump 14 .
- formed on the lower header 20 is the annular receiving part 20 slidably engaged with the inner wall 18 a and the outer wall 18 b of the upper header 18 . Since the structures of the upper header 18 and the lower header 20 can be simplified, reduction in cost can be achieved
- FIG. 10 is a view showing a sealing structure around an electromagnetic pump in the fifth embodiment of the present invention.
- the fifth embodiment shown in FIG. 10 is substantially the same as the first embodiment shown in FIGS. 1 to 6 , excluding that an intermediate heat exchanger and an electromagnetic pump are connected in series with each other in an up and down direction.
- the same elements as those of the first embodiment shown in FIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted.
- an intermediate heat exchanger 15 and an electromagnetic pump 14 are connected in series with each other in an up and down direction.
- a coolant guide mechanism 17 configured to guide a pressurized primary coolant 21 from the electromagnetic pump 14 toward a neutron shield 8 through an opening 29 a of the upper supporting plate 29 .
- FIG. 11 is a view showing a fast reactor in the sixth embodiment of the present invention.
- a core supporting mechanism disposed in the reactor vessel, which horizontally extends so as to support the core is formed of the upper supporting plate, and the coolant guide mechanism configured to guide the pressurized coolant from the pump for coolant is connected to the opening of the upper supporting plate, which is by way of example.
- the core supporting mechanism may be formed of a core support supporting the core from below and having an opening to which a coolant guide mechanism is connected.
- FIG. 11 a fast reactor in the sixth embodiment of the present invention is described with reference to FIG. 11 .
- the same elements as those of the first embodiment shown in FIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted.
- annular intermediate heat exchanger 15 configured to cool a primary coolant 21 which has been heated by a core 2 is disposed between an upper supporting plate 29 and an inner surface of a reactor vessel 7 .
- annular electromagnetic pump 14 which is configured to pressurize the primary coolant that has passed through the intermediate heat exchanger 15 so as to be cooled, is disposed around a core 2 .
- the electromagnetic pump 14 is connected in series with the intermediate heat exchanger 15 in an up and down direction.
- a plurality of, e.g., two annular electromagnetic pumps 14 are connected in series with each other in the up and down direction.
- the height of the fast reactor 1 can be shortened.
- a material used for the reactor vessel 7 and the like of the fast reactor 1 can be reduced, whereby costs for the fast reactor 1 can be further reduced.
- the fast reactor 1 can be further stabilized, whereby a quake-resistance or the like of the fast reactor 1 can be improved.
- a core support 13 supporting the core 2 from below is provided with an opening 13 a through which the pressurized coolant 21 from the electromagnetic pump 14 passes.
- a coolant guide mechanism 17 configured to guide a pressurized primary coolant 21 from the electromagnetic pump 14 toward a lower plenum 33 through the opening 13 a of the core support 13 .
- the pressurized primary coolant 21 of about 350° C. leaks to the higher temperature zone 25 , and that a pressure difference between the lower temperature and higher pressure zone 24 and the higher temperature zone 25 is applied to the lower bulkhead 6 a .
- lowering of a power generation efficiency of the fast reactor 1 can be prevented, as well as reliability of the fast reactor 1 can be enhanced.
- the configuration of the coolant guide mechanism 17 shown in FIG. 11 is not particularly limited.
- the coolant guide mechanism 17 may be composed of an annular upper header 18 mounted on the outlet 14 b of the electromagnetic pump 14 , and an annular lower header 20 disposed below the upper header 18 such that the lower header 20 is mounted on the core support 13 so as to cover an opening 13 a of the core support 13 from above.
- the upper header 18 may be provided with a plurality of nozzles 19 in a circumferential direction thereof. Each of the nozzles 19 projects downward and passes therethrough the pressurized primary coolant 21 from the electromagnetic pump 14 .
- the lower header 20 may be provided with a plurality of nozzle receivers 20 a which are slidably engaged with the corresponding nozzles 19 of the upper header 18 .
- the respective nozzles 19 may be connected to the upper header 18 through the spherical seating seals 19 b.
- the upper header 18 may include the annular inner wall 18 a extending downwardly from the outlet 14 b of the electromagnetic pump 14 , and the annular outer wall 18 b extending downwardly from the outlet 14 b of the electromagnetic pump 14 .
- formed on the lower header 20 may be the annular receiving part 20 b slidably engaged with the inner wall 18 a of the upper header 18 and the outer wall 18 b thereof.
- FIG. 12 is a view showing a fast reactor in the seventh embodiment of the present invention.
- the seventh embodiment shown in FIG. 12 is substantially the same as the sixth embodiment shown in FIG. 11 , excluding that a pump for coolant includes a plurality of pumps (mechanical pumps, electromagnetic pumps, etc.) disposed around a core.
- a pump for coolant includes a plurality of pumps (mechanical pumps, electromagnetic pumps, etc.) disposed around a core.
- the same elements as those of the sixth embodiment shown in FIG. 11 are shown by the same reference numbers, and detailed description thereof is omitted.
- an annular intermediate heat exchanger 15 configured to cool a primary coolant 21 which has been heated by a core 2 is disposed between an upper supporting plate 29 and an inner surface of a reactor vessel 7 .
- the heat exchanger 15 is structured such that the heat exchanger 15 can be connected in series with a plurality of electromagnetic pumps 14 disposed around the core 2 in an up and down direction.
- the one electromagnetic pump 14 disposed around the core 2 is connected in series with the intermediate heat exchanger 15 in the up and down direction.
- the other electromagnetic pump 14 may be connected in series with the intermediate heat exchanger 15 in the up and down direction.
- the number of the electromagnetic pumps 14 to be disposed around the core 2 can be suitably set depending on the specification of the fast reactor 1 .
- a coolant guide mechanism 17 configured to guide a pressurized primary coolant 21 from the electromagnetic pumps 14 toward a lower plenum 33 through an opening 13 a of the core support 13 .
- the primary coolant 21 can be separated from its circumference by the coolant guide mechanism 17 , from when the primary coolant 21 is discharged from the electromagnetic pumps 14 until when the primary coolant 21 reaches the opening 13 a of the core support 13 . Therefore, it can be prevented that the pressurized primary coolant 21 of about 350° C.
- FIG. 13 is a fast reactor in the eight embodiment of the present invention.
- the eighth embodiment shown in FIG. 13 is substantially the same as the seventh embodiment shown in FIG. 12 , excluding that a coolant guide mechanism is connected to a lower plenum disposed on a core support.
- the same elements as those of the seventh embodiment shown in FIG. 12 are shown by the same reference numbers, and detailed description thereof is omitted.
- a coolant guide mechanism 17 includes an upper header 18 mounted on an outlet 14 b of an electromagnetic pump 14 , and a lower header 20 passing through an opening 13 a of a core support 13 , with one end of the lower header 20 being engaged with the upper header 18 and the other end thereof being connected to a lower plenum 33 of the core support 13 . Since the outlet 14 b of the electromagnetic pump 14 and the lower plenum 33 is connected to each other by means of the coolant guide mechanism 17 , the primary coolant 21 can be guided up to the lower plenum 33 without diminishing its flow rate. Thus, the efficiency of a fast reactor 1 can be enhanced.
- FIG. 14 is a fast reactor in the ninth embodiment of the present invention.
- the ninth embodiment shown in FIG. 14 is substantially the same as the first embodiment shown in FIGS. 1 to 6 , excluding that a lower header is formed of a nozzle receiver disposed on an upper supporting plate.
- the same elements as those of the first embodiment shown in FIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted.
- a coolant guide mechanism 17 includes an annular upper header 18 mounted on an outlet 14 b of an electromagnetic pump 14 , and an annular lower header 20 disposed below the upper header 18 and is mounted on an upper supporting plate 29 .
- the upper header 18 is provided with a plurality of nozzles 19 in a circumferential direction thereof. Each of the nozzles 19 projects downward and passes therethrough a pressurized primary coolant 21 from the electromagnetic pump 14 .
- the lower header 20 is formed of a plurality of nozzle receivers 27 slidably engaged with the nozzles 19 of the upper header 18 .
- An annular seal 19 a is interposed between the nozzles 19 and the nozzle receivers 27 .
- each of the nozzle receivers 27 includes a receiving part 27 b slidably engaged with the nozzle 19 of the upper header 18 , and a tapered receiving base 27 a configured to guide the corresponding nozzle 19 of the upper header 18 to the receiving part 27 b .
- the nozzle receiver 27 is fixed on the upper supporting plate 29 by means of a clamp 27 c .
- a sealing member 51 is interposed between the nozzle receiver 27 and the upper supporting plate 29 .
- the lower header 20 formed of the nozzle receivers 27 is fixed on the upper supporting plate 29 , which is by way of example.
- the lower header 20 formed of the nozzle receivers 27 may be fixed on a core support 13 .
- the lower header 20 formed of the nozzle receivers 27 may be used.
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Abstract
Description
- The present invention relates to a fast reactor, in particular, a fast reactor having a high coolant sealing property and an excellent maintainability.
- In a fast reactor, an effort for reducing a leakage amount of coolant from a sealing part has been conventionally exerted. The
below Patent Document 1 shows an example of a conventional fast reactor, which is shown inFIG. 15 . - As shown in
FIG. 15 , thefast reactor 1 described inPatent Document 1 includes acore 2 formed of a nuclear fuel assembly. Thecore 2 has a substantially cylindrical shape as a whole. An outer circumference of thecore 2 is surrounded by acore barrel 3. Areflector 4 surrounding thecore barrel 3 is located outside thecore barrel 3. Outside thereflector 4, there is disposed abulkhead 6 that surrounds thereflector 4 and constitutes an inner wall of a flow path through which a primary coolant 21 (coolant) flows. Areactor vessel 7 constituting an outer wall of the flow path of theprimary coolant 21 is located outside thebulkhead 6, with a predetermined clearance therebetween. Aneutron shield 8 is disposed in the flow path of theprimary coolant 21 such that theneutron shield 8 surrounds thecore 2. Thecore 2, thecore barrel 3, thebulkhead 6 and theneutron shield 8 are respectively supported by acore support 13 from below. - In
FIG. 15 , after theprimary coolant 21 is pressurized by anelectromagnetic pump 14, theprimary coolant 21 passes through theneutron shield 8 and the core supports 13 and then reaches thecore 2, whereby thecored 2 is cooled. Theprimary coolant 21 heated by thecore 2 while passing therethrough is sent to anintermediate heat exchanger 15. In theintermediate heat exchanger 15, the heat is exchanged between theprimary coolant 21 and asecondary coolant 31. In order to facilitate a maintenance operation, theintermediate heat exchanger 15 is configured to be drawn from thereactor vessel 7. In this case, a seal bellows attached to the intermediate heat exchanger is seated on a bellows seat fixed on thebulkhead 6. The seal bellows is compressed by a weight of theintermediate heat exchanger 15. Thus, the pressurizedprimary coolant 21 from an outlet of theelectromagnetic pump 14 can be sealed against the heatedprimary coolant 21 inside thebulkhead 6. - Patent Document 1: JP5-119175A
- In the
fast reactor 1 described inPatent Document 1, when sodium is used as theprimary coolant 21, it is considered that a temperature of theprimary coolant 21 in a zone (higher temperature zone) from an outlet of thecore 2 to an inlet of theintermediate heat exchanger 15 is about 500° C., and that a temperature of theprimary coolant 21 in a zone (lower temperature zone) from an outlet of theintermediate heat exchanger 15 to an inlet of thecore 2 is about 350° C. Namely, the structural member supporting thecore 2 is used under such conditions as a high temperature and a large temperature difference. In particular, since thebulkhead 6 constituting the inner wall of the flow path of theprimary coolant 21 also experiences a large pressure difference between the higher temperature zone and the lower temperature zone, in addition to the above temperature difference, thebulkhead 6 is exposed to an extremely severe environment. - In order to prevent that the
primary coolant 21 in the higher temperature zone leaks into the lower temperature zone over thebulkhead 6 and that theprimary coolant 21 in the lower temperature zone leaks into the higher temperature zone over thebulkhead 6, there have been heretofore proposedvarious seal structures fast reactor 1 described inPatent Document 1. However, as described above, theseseal structures - When a sealing function of the
bulkhead 6 is insufficient, there is a possibility that the pressurizedprimary coolant 21 of a lower temperature from the outlet of theelectromagnetic pump 14 might flow into theprimary coolant 21 in the higher temperature zone at the outlet of thecore 2. In this case, a temperature difference between the inlet and the outlet of theintermediate heat exchanger 15 is possibly decreased, resulting in deterioration of the heat exchanging function. Thus, a heat balance of thefast reactor 1 may be lost, which induces a large impact on an output of a plant. In addition, since a flow amount of theprimary coolant 21 for cooling thecore 2 is lost, there is a possibility that a temperature of thecore 2 might increase, whereby a safety of thefast reactor 1 is lowered. - In addition, in the conventional
fast reactor 1, theintermediate heat exchanger 15 and theelectromagnetic pump 14 are arranged in series with each other. Thus, if theelectromagnetic pump 14 having a higher failure probability is damaged, theelectromagnetic pump 14 and theintermediate heat exchanger 15 should be simultaneously pulled out. In this case, since these equipments are radioactivated, it is necessary to exchange both of the equipments. Further, since a huge cask for storing these equipments or for bringing these equipments to a disposal place is needed, an enormous cost is required. - The present invention has been made in view of the above circumstances. The object of the present invention is to provide a fast reactor having a high primary coolant sealing property and an excellent maintainability.
- According to the present invention, a fast reactor comprises:
- a reactor vessel accommodating therein a core and a coolant;
- a core supporting mechanism disposed in the reactor, the core supporting mechanism extending horizontally so as to support the core;
- a bulkhead extending in parallel with the core and surrounding the core from a lateral side;
- an intermediate heat exchanger disposed between an inner surface of the reactor vessel and the bulkhead, the intermediate heat exchanger being configured to cool the coolant that has been heated by the core;
- a pump for coolant disposed between the inner surface of the reactor vessel and the bulkhead, the pump for coolant being configured to pressurize the coolant that has passed through the intermediate heat exchanger so as to be cooled; and
- a lower plenum structured below the core supporting mechanism, the lower plenum being configured to guide the coolant which has been pressurized by the pump for coolant to the core;
- wherein:
- the core supporting mechanism is provided with an opening through which the pressurized coolant from the pump for coolant passes; and
- disposed between an outlet of the pump for coolant and the core supporting mechanism is a coolant guide mechanism configured to guide the pressurized coolant from the pump for coolant to the lower plenum through the opening of the core supporting mechanism.
- The fast reactor according to the present invention may further comprise a neutron shield located below the pump for coolant,
- wherein the core supporting mechanism is formed of an upper supporting plate disposed between the pump for coolant and the neutron shield so as to support the neutron shield, the upper support plate having an opening to which the coolant guide mechanism is connected.
- In this case, the coolant guide mechanism may include an upper header mounted on the outlet of the pump for coolant, and a lower header disposed below the upper header and mounted on the upper supporting plate, the upper header may be provided with a downwardly projecting nozzle through which the pressurized coolant from the pump for coolant passes, and the lower header may be provided with a nozzle receiver slidably engaged with the nozzle of the upper header.
- Alternatively, the coolant guide mechanism may include an annular upper header mounted on the outlet of the pump for coolant, and an annular lower header disposed below the upper header and mounted on the upper supporting plate, the upper header may include an annular inner wall extending downwardly from the outlet of the pump for coolant and an annular outer wall extending downwardly from the outlet of the pump for coolant, and the lower header may include an annular receiving part slidably engaged with the inner wall of the upper header and the outer wall of the upper header.
- In the fast reactor according to the present invention, the core supporting mechanism may be formed of a core support supporting the core from below and having an opening to which the coolant guide mechanism is connected.
- In this case, the coolant guide mechanism may include an upper header mounted on the outlet of the pump for coolant, and a lower header disposed below the upper header and mounted on the core support, and the upper header may be provided with a downwardly projecting nozzle through which the pressurized coolant from the pump for coolant passes, and the lower header may be provided with a nozzle receiver slidably engaged with the nozzle of the upper header.
- Alternatively, the coolant guide mechanism may include an annular upper header mounted on the outlet of the pump for coolant, and an annular lower header disposed below the upper header and mounted on the core support, the upper header may include an annular inner wall extending downwardly from the outlet of the pump for coolant and an annular outer wall extending downwardly from the outlet of the pump for coolant, and the lower header may include an annular receiving part slidably engaged with the inner wall of the upper header and the outer wall of the upper header.
- The fast reactor according to the present invention may further comprise:
- a neutron shield located below the pump for coolant; and
- an upper supporting plate disposed between the pump for coolant and the neutron shield so as to support the neutron shield;
- wherein:
- the coolant guide mechanism includes an upper header mounted on the outlet of the pump for coolant, and a pipe passing through the upper supporting plate with one end of the pipe being engaged with the upper header and the other end thereof being connected to the core support;
- the upper header is provided with a downwardly projecting nozzle through which the pressurized coolant from the pump for coolant passes; and
- the one end of the pipe is slidably engaged with the nozzle of the upper header.
- In the fast reactor according to the present invention, the nozzle may be connected to the upper header through a spherical seating seal.
- In the fast reactor according to the present invention, the upper header may be provided with a plurality of nozzles, and at least one of the nozzles is longer than the other nozzle(s).
- In the fast reactor according to the present invention, when seen from above, the pump for coolant may be arranged on a position nearer to the core than the intermediate heat exchanger, such that the pump for coolant and the intermediate heat exchanger do not overlap with each other.
- In the fast reactor according to the present invention, a part of the bulkhead, which is located above the upper supporting plate, may be formed of a manometerseal.
- According to the present invention, in the fast reactor comprising the reactor vessel accommodating therein the core and the coolant, the pump for coolant, which is configured to pressurize the coolant that has passed through an intermediate heat exchanger so as to be cooled, is disposed between the inner surface of the reactor vessel and the bulkhead, and the neutron shield is disposed below the pump for coolant. In addition, the upper supporting plate supporting the neutron shield is disposed between the pump for coolant and the neutron shield. The upper supporting plate has the opening through which the pressurized coolant from the pump for coolant passes. Disposed between the outlet of the pump for coolant and the upper supporting plate is the coolant guide mechanism configured to guide the pressurized coolant from the pump for coolant toward the neutron shield through the opening of the upper supporting plate. Thus, the coolant of a lower temperature, which has been cooled by the intermediate heat exchanger and pressurized by the pump for coolant, can be guided by the coolant guide mechanism toward the neutron shield through the opening of the upper supporting plate. Therefore, there is no possibility that the coolant of a lower temperature, which has been pressurized by the pump for coolant, leaks to the coolant of a higher temperature, which has been heated by the core, through the bulkhead, whereby it is possible to improve a sealing property between the coolant of a lower temperature, which has been pressurized by the pump for coolant, and the coolant of a higher temperature, which has been heated by the core. As a result, lowering of a power generation efficiency of the fast reactor can be prevented, as well as reliability of the fast reactor can be enhanced.
-
FIG. 1 is a view showing a fast reactor in a first embodiment of the present invention. -
FIG. 2 is a view showing a sealing structure around an electromagnetic pump in the first embodiment of the present invention. -
FIG. 3 is a view showing a coolant guide mechanism in the first embodiment of the present invention. -
FIG. 4( a) is a view showing an upper header when seen from above in the first embodiment of the present invention. -
FIG. 4( b) is a view showing the upper header when seen from below in the first embodiment of the present invention. -
FIG. 4( c) is a view showing a nozzle of the upper header in enlargement. -
FIG. 5( a) is a view showing a lower header when seen from above in the first embodiment of the present invention. -
FIG. 5( b) is a view showing the lower header when seen from below in the first embodiment of the present invention. -
FIG. 6( a) is a view showing that the upper header and the lower header are connected to each other in the first embodiment of the present invention. -
FIG. 6( b) is a sectional view showing that the upper header and the lower header are connected to each other in the first embodiment of the present invention. -
FIG. 7 is a view showing a coolant guide mechanism in a second embodiment of the present invention. -
FIG. 8 is a view showing a coolant guide mechanism in a third embodiment of the present invention. -
FIG. 9 is a view showing a coolant guide mechanism in a fourth embodiment of the present invention. -
FIG. 10 is a view showing a sealing structure around an electromagnetic pump in a fifth embodiment of the present invention. -
FIG. 11 is a view showing a fast reactor in a sixth embodiment of the present invention. -
FIG. 12 is a view showing a fast reactor in a seventh embodiment of the present invention. -
FIG. 13 is a view showing a fast reactor in an eighth embodiment of the present invention. -
FIG. 14 is a view showing a fast reactor in a ninth embodiment of the present invention. -
FIG. 15 is a view showing a conventional fast reactor. - A first embodiment of the present invention will be described herebelow with reference to the drawings.
-
FIG. 1 to 6 are views showing a fast reactor in the first embodiment of the present invention. - At first, a
fast reactor 1 in this embodiment is generally described with reference toFIG. 1 . - As shown in
FIG. 1 , thefast reactor 1 includes: areactor vessel 7 accommodating there in acore 2 formed of a nuclear fuel assembly containing plutonium, and a primary coolant (coolant) 21 formed of liquid sodium; acore support 13 disposed in thereactor vessel 7 so as to support thecore 2 from below; acore barrel 3 disposed on thecore support 13 so as to surround thecore 2 from a lateral side; areflector 4 disposed so as to surround thecore barrel 3; and an upwardly extendingbulkhead 6 disposed on thecore support 13 so as to surround thecore 2, thecore barrel 3 and thereflector 4 from the lateral side. Thereflector 4 is composed of aneutron reflecting part 4 a and ahollow cavity part 4 b. An inert gas or a metal having a lower neutron reflection ability than that of theprimary coolant 21 is enclosed in the hollow space of thecavity part 4 b. - In addition, as shown in
FIG. 1 , disposed between an inner surface of thereactor vessel 7 and thebulkhead 6 is an annularintermediate heat exchanger 15 configured to cool theprimary coolant 21 which has been heated by thecore 2. A pump for coolant, e.g., an annularelectromagnetic pump 14 configured to pressurize theprimary coolant 21 that has passed through theintermediate heat exchanger 15 so as to be cooled is disposed between the inner surface of thereactor vessel 7 and thebulkhead 6 at a position near to theintermediate heat exchanger 15. - A
neutron shield 8 is disposed between the inner surface of thereactor vessel 7 and thebulkhead 6 at a position below theelectromagnetic pump 14. As shown inFIG. 1 , disposed between theneutron shield 8 and theelectromagnetic pump 14 is an upper supportingplate 29 supporting theneutron shield 8 from above. - The
bulkhead 6 is composed of alower bulkhead 6 a surrounding thecore 2,core barrel 3 and thereflector 4 from the lateral side, and anupper bulkhead 6 b surrounding theprimary coolant 21 which has been heated by thecore 2. Thelower bulkhead 6 a is mounted on the upper supportingplate 29 through a sealing member (not shown), such that thelower bulkhead 6 a is slidable in an up and down direction. Thus, when thelower bulkhead 6 a extends or contracts in the up and down direction by thermal expansion, thelower bulkhead 6 a can be slid in the up and down direction with respect to the upper supportingplate 29. - Next, a structure around the
electromagnetic pump 14 is described with reference toFIG. 2 . As shown inFIG. 2 , the upper supportingplate 29 has anopening 29 a through which the pressurizedprimary coolant 21 from theelectromagnetic pump 14 passes. Between anoutlet 14 b of the electromagnetic pump and the upper supportingplate 29, there is disposed acoolant guide mechanism 17 configured to guide the pressurizedprimary coolant 21 from theelectromagnetic pump 14 toward theneutron shield 8 through the opening 29 a of the upper supportingplate 29. - As described below, the
primary coolant 21 guided toward theneutron shield 8 passes through anopening 13 a of thecore support 13 to flow into alower plenum 33 shown inFIG. 2 . Thereafter, theprimary coolant 21 moves upward while cooling thecore 2. Theprimary coolant 21 which has been heated by thecore 2 reaches anupper plenum 32 shown inFIG. 1 , and then flows into aninlet 15 a of theintermediate heat exchanger 15 over theupper bulkhead 6 b. After theprimary coolant 21 has been cooled in theintermediate heat exchanger 15, theprimary coolant 21 outflows from anoutlet 15 b of theintermediate heat exchanger 15. Then, theprimary coolant 21 is sucked into aninlet 14 a of theinlet 14 a of theelectromagnetic pump 14. In this embodiment, as shown inFIG. 2 , a zone filled with theprimary coolant 21, which has been cooled by theintermediate heat exchanger 15 and is not yet pressurized by theelectromagnetic pump 14, provides a lower temperature andlower pressure zone 23. Further, a zone filled with theprimary coolant 21, which has been pressurized by theelectromagnetic pump 14 and is not yet heated by thecore 2, provides a lower temperature andhigher pressure zone 24. Furthermore, a zone filled with theprimary coolant 21, which has been heated by thecore 2 and is not yet cooled by theintermediate heat exchanger 15, provides ahigher temperature zone 25. - As shown in
FIG. 2 , when seen from above, the annularelectromagnetic pump 14 is arranged on a position nearer to thecore 2 than theintermediate heat exchanger 15, such that the annularelectromagnetic pump 14 and the annularintermediate heat exchanger 15 do not overlap with each other. Thus, when thefast reactor 1 is repaired or maintained, theelectromagnetic pump 14 can be independently pulled out upward, while theintermediate heat exchanger 15 remains in thefast reactor 1. - In general, since a failure rate of the
electromagnetic pump 14 is higher than a failure rate of theintermediate heat exchanger 15, theelectromagnetic pump 14 should be more frequently replaced. At this time, suppose that theintermediate heat exchanger 15 and theelectromagnetic pump 14 are arranged to be overlapped with each other, when seen from above. Under such a structure, when the brokenelectromagnetic pump 14 is replaced, theelectromagnetic pump 14 is pulled out together with theintermediate heat exchanger 15. In this case, since theelectromagnetic pump 14 and theintermediate heat exchanger 15 are both radioactivated, not only the brokenelectromagnetic pump 14 but also theintermediate heat exchanger 15, which is not broken, should be replaced. - On the other hand, according to this embodiment, when seen from above, the annular
electromagnetic pump 14 is arranged on a position nearer to thecore 2 than theintermediate heat exchanger 15, such that the annularelectromagnetic pump 14 and the annularintermediate heat exchanger 15 do not overlap with each other. Thus, as compared with the case in which theintermediate heat exchanger 15 and theelectromagnetic pump 14 are arranged to be overlapped with each other, when seen from above, costs required for maintaining thefast reactor 1 can be reduced. - In addition, as shown in
FIG. 2 , concerning theupper bulkhead 6 b of thebulkhead 6, which is located above the upper supportingplate 29, a part of theupper bulkhead 6 b, which is located near to theelectromagnetic pump 14 at a position nearer to thecore 2 than theelectromagnetic pump 14, and a part of theupper bulkhead 6 b, which is located near to theelectromagnetic pump 14 between theelectromagnetic pump 14 and theintermediate heat exchanger 15, are respectively formed ofmanometerseals 34. Due to these manometer seals 34, at the position near to theelectromagnetic pump 14, it can be securely prevented that theprimary coolant 21 in the lower temperature andlower pressure zone 23 leaks to thehigher temperature zone 25, and that theprimary coolant 21 in thehigher temperature zone 25 leaks to the lower temperature andlower pressure zone 23. In addition, therespective manometerseals 34 are filled with aninert gas 35, whereby the heat can be prevented from moving from thehigher temperature zone 25 to the lower temperature andlower pressure zone 23. - Next, the
coolant guide mechanism 17 is described in detail, with reference toFIGS. 3 to 6 . As shown inFIG. 3 , thecoolant guide mechanism 17 is composed of an annularupper header 18 mounted on theoutlet 14 b of theelectromagnetic pump 14, and an annularlower header 20 disposed below theupper header 18 such that thelower header 20 is mounted on the upper supportingplate 29 so as to cover anopening 29 a of the upper supportingplate 29 from above. As shown inFIGS. 4( a), 4(b) and 4(c), theupper header 18 is provided with a plurality ofnozzles 19 in a circumferential direction thereof. Each of thenozzles 19 projects downward and passes therethrough the pressurizedprimary coolant 21 from theelectromagnetic pump 14. As shown inFIGS. 5( a) and 5(b) andFIGS. 6( a) and 6(b), thelower header 20 is provided with a plurality ofnozzle receivers 20 a which are slidably engaged with the correspondingnozzles 19 of theupper header 18. Owing to such acoolant guide mechanism 17, the pressurizedprimary coolant 21 from theelectromagnetic pump 14 can be guided toward theneutron shield 8 through the opening 29 a of the upper supportingplate 29, with the pressurizedprimary coolant 21 from theelectromagnetic pump 14 being shielded from theprimary coolant 21 in the lower temperature andlower pressure zone 23. - As shown in
FIG. 3 , twoannular seals 19 a are interposed between thenozzles 19 and thenozzle receivers 20 a. As shown inFIG. 3 , a sealingmember 51 is interposed between a lower surface of thelower header 20 and an upper surface of the upper supportingplate 29. Thus, the pressurizedprimary coolant 21 from theelectromagnetic pump 14 can be more securely shielded from theprimary coolant 21 in the lower temperature andlower pressure zone 23. - As shown by the two-dot chain lines in
FIG. 4( b), at least one of thenozzles 19 of theupper header 18 may be formed by alonger nozzle 19 c which is longer than theother nozzles 19. - Next, an operation of this embodiment as structured above is described. Herein, the flow of the
primary coolant 21 in thefast reactor 1 is described. - After the
primary coolant 21 which had been heated by thecore 2, e.g., theprimary coolant 21 of a temperature of about 500° C., has reached theupper plenum 32 shown inFIG. 1 , theprimary coolant 21 flows into theinlet 15 a of theintermediate heat exchanger 15 over theupper bulkhead 6 b. In theintermediate heat exchanger 15, the heat is exchanged between theprimary coolant 21 and asecondary coolant 31 shown inFIG. 1 , whereby theprimary coolant 21 is cooled and thesecondary coolant 31 is heated. The temperature of theprimary coolant 21, which has been cooled in theintermediate heat exchanger 15, is about 350° C., for example. - The
primary coolant 21, which has been cooled in theintermediate heat exchanger 15, outflows from theoutlet 15 b of theintermediate heat exchanger 15. Then, theprimary coolant 21 is sucked into theinlet 14 a of theelectromagnetic pump 14. Theprimary coolant 21 having been sucked into theinlet 14 a of theelectromagnetic pump 14 is pressurized at theelectromagnetic pump 14. Thereafter, theprimary coolant 21 is discharged from theoutlet 14 b of theelectromagnetic pump 14. Theprimary coolant 21 having been discharged from theoutlet 14 b of theelectromagnetic pump 14 is guided toward theneutron shield 8 through thecoolant guide mechanism 17 and theopening 29 a of the upper supportingplate 29. - The
primary coolant 21 having been guided toward theneutron shield 8 then flows into thelower plenum 33 shown inFIGS. 1 and 2 through the opening 13 a of thecore support 13. After that, as shown inFIGS. 1 and 2 , theprimary coolant 21 moves upward while cooling thecore 2. - Upon discharge of the pressurized
primary coolant 21 of about 350° C. from theoutlet 14 b of theelectromagnetic pump 14, theprimary coolant 21 having been discharged from theoutlet 14 b of theelectromagnetic pump 14 is guided by thecoolant guide mechanism 17 toward theneutron shield 8 through the opening 29 a of the upper supportingplate 29. Outside thecoolant guide mechanism 17, there is formed the lower temperature andlower pressure zone 23 that is filled with theprimary coolant 21 of about 350° C., which is not yet pressurized. The lower temperature andlower pressure zone 23 is in contact with thehigher temperature zone 25, which is filled with theprimary coolant 21 of about 500° C. that has been heated by thecore 2, through theupper bulkhead 6 b. Namely, the lower temperature andhigher pressure zone 24, which is filled with the pressurizedprimary coolant 21 of about 350° C., is not in contact with thehigher temperature zone 25, which is filled with theprimary coolant 21 of about 500° C. that has been heated by thecore 2, through theupper bulkhead 6 b. Thus, it can be prevented that the pressurizedprimary coolant 21 of about 350° C. leaks to thehigher temperature zone 25, and that a pressure difference between the lower temperature andhigher pressure zone 24 and thehigher temperature zone 25 is applied to theupper bulkhead 6 b. As a result, lowering of a power generation efficiency of thefast reactor 1 can be prevented, as well as reliability of thefast reactor 1 can be enhanced. - In this embodiment, the
higher temperature zone 25 and the lower temperature andlower pressure zone 23 are in contact with each other through theupper bulkhead 6 b. Here, a pressure difference between thehigher temperature zone 25 and the lower temperature andlower pressure zone 23, which is about several Kpa, is substantially equal to a pressure loss in theintermediate heat exchanger 15. Thus, as shown inFIG. 2 , when themanometerseal 34 is used as theupper bulkhead 6 b, a difference in height between aliquid level 34 a in thehigher temperature zone 25 and aliquid level 34 b in the lower temperature andlower pressure zone 23 is about several hundreds mm. Thus, leakage of theprimary coolant 21 between thehigher temperature zone 25 and thezone 23 of a lower temperature and a lower temperature can be substantially made zero. - According to this embodiment, between the
outlet 14 b of theelectromagnetic pump 14 and the upper supportingplate 29, there is provided thecoolant guide mechanism 17 configured to guide the pressurizedprimary coolant 21 from theelectromagnetic pump 14 toward theneutron shield 8 through the opening 29 a of the upper supportingplate 29. Thus, theprimary coolant 21 of a lower temperature, which has been cooled by theintermediate heat exchanger 15 and pressurized by theelectromagnetic pump 14, can be guided by thecoolant guide mechanism 17 toward theneutron shield 8 through the opening 29 a of the upper supportingplate 29. Therefore, there is no possibility that theprimary coolant 21 of a lower temperature, which has been pressurized by theelectromagnetic pump 14, leaks to theprimary coolant 21 of a higher temperature, which has been heated by thecore 2, through the bulkhead, whereby it is possible to improve a sealing property between theprimary coolant 21 of a lower temperature, which has been pressurized by theelectromagnetic pump 14, and theprimary coolant 21 of a higher temperature, which has been heated by thecore 2. As a result, lowering of a power generation efficiency of thefast reactor 1 can be prevented, as well as reliability of thefast reactor 1 can be enhanced. - In addition, according to this embodiment, the
coolant guide mechanism 17 is composed of the annularupper header 18 mounted on theoutlet 14 b of theelectromagnetic pump 14, and the annularlower header 20 disposed below theupper header 18 such that thelower header 20 is mounted on the upper supportingplate 29 so as to cover theopening 29 a of the upper supportingplate 29 from above. Theupper header 18 is provided with a plurality ofnozzles 19 in a circumferential direction thereof. Each of thenozzles 19 projects downward and passes therethrough the pressurizedprimary coolant 21 from theelectromagnetic pump 14. Thelower header 20 is provided with a plurality ofnozzle receivers 20 a which are slidably engaged with the correspondingnozzles 19 of theupper header 18. In addition, the twoannular seals 19 a are interposed between thenozzles 19 and thenozzle receivers 20 a. Thus, it can be prevented that the pressurizedprimary coolant 21 from theelectromagnetic pump 14 leaks to the lower temperature andlower pressure zone 23, which is filled with theprimary coolant 21 that is not yet pressurized. - In addition, according to this embodiment, when seen from above, the annular
electromagnetic pump 14 is arranged on a position nearer to thecore 2 than theintermediate heat exchanger 15, such that the annularelectromagnetic pump 14 and the annularintermediate heat exchanger 15 do not overlap with each other. Thus, when thefast reactor 1 is repaired or maintained, theelectromagnetic pump 14 can be independently pulled out upward, while theintermediate heat exchanger 15 remains in thefast reactor 1. Thus, as compared with the case in which theintermediate heat exchanger 15 and theelectromagnetic pump 14 are arranged to be overlapped with each other, when seen from above, costs required for maintaining thefast reactor 1 can be reduced. - In addition, according to this embodiment, a part of the
upper bulkhead 6 b, which is located near to theelectromagnetic pump 14 at a position nearer to thecore 2 than theelectromagnetic pump 14, and a part of theupper bulkhead 6 b, which is located near to theelectromagnetic pump 14 between theelectromagnetic pump 14 and theintermediate heat exchanger 15, are respectively formed of themanometerseals 34. Due to thesemanometerseals 34, at the position near to theelectromagnetic pump 14, it can be securely prevented that theprimary coolant 21 in the lower temperature andlower pressure zone 23 leaks to thehigher temperature zone 25, and that theprimary coolant 21 in thehigher temperature zone 25 leaks to the lower temperature andlower pressure zone 23. In addition, therespective manometerseals 34 are filled with theinert gas 35, whereby the heat can be prevented from moving from thehigher temperature zone 25 to the lower temperature andlower pressure zone 23. - In this embodiment, the pump for coolant is formed of the
electromagnetic pump 14, which is by way of example. However, not limited thereto, a mechanical pump or another pump may be used as the pump for coolant. - In addition, in this embodiment, the annular
intermediate heat exchanger 15 and the annularelectromagnetic pump 14 are provided, which is by way of example. However, not limited thereto, a plurality ofintermediate heat exchangers 15 and a plurality ofelectromagnetic pumps 14 may be circumferentially arranged. In this case, theelectromagnetic pump 14 can be pulled out upward more easily. - In addition, in this embodiment, a part of the
upper bulkhead 6 b, which is located near to theelectromagnetic pump 14 at a position nearer to thecore 2 than theelectromagnetic pump 14, and a part of theupper bulkhead 6 b, which is located near to theelectromagnetic pump 14 between theelectromagnetic pump 14 and theintermediate heat exchanger 15, are respectively formed of themanometerseals 34, which is by way of example. However, not limited thereto, themanometerseal 34 may be used only on one of a part which is located near to theelectromagnetic pump 14 at a position nearer to thecore 2 than theelectromagnetic pump 14, and a part which is located near to theelectromagnetic pump 14 between theelectromagnetic pump 14 and theintermediate heat exchanger 15. - In addition, in this embodiment, when a flowmeter (not shown) is placed on a lower end of the
electromagnetic pump 14, theupper header 18 may be placed below the flowmeter. - Next, a second embodiment of the present invention is described with reference to
FIG. 7 .FIG. 7 is a view showing a coolant guide mechanism in the second embodiment of the present invention. - The second embodiment shown in
FIG. 7 is substantially the same as the first embodiment shown inFIGS. 1 to 6 , excluding that respective nozzles are connected to an upper header through spherical seating seals. In the second embodiment shown inFIG. 7 , the same elements as those of the first embodiment shown inFIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted. - As shown in
FIG. 7 ,respective nozzles 19 of acoolant guide mechanism 17 are connected to anupper header 18 through spherical seating seals 19 b. Thus, eachnozzle 19 can be optionally inclined within a predetermined range with respect to theupper header 18. Therefore, a manufacturing tolerance and an installation tolerance of thecoolant guide mechanism 17 can be absorbed, as well as a structural deformation of thecoolant guide mechanism 17, which is caused during the operation of afast reactor 1, can be absorbed. In addition, alignment of eachnozzle 19 with a correspondingnozzle receiver 20 a of alower header 20 can be facilitated. - According to this embodiment, the
respective nozzles 19 of thecoolant guide mechanism 17 are connected to theupper header 18 through the spherical seating seals 19 b. Thus, it can be prevented that the pressurizedprimary coolant 21 from theelectromagnetic pump 14 leaks to the lower temperature andlower pressure zone 23, which is filled with theprimary coolant 21 that is not yet pressurized. In addition, installation of thefast reactor 1 can be facilitated, and maintainability of thefast reactor 1 can be enhanced. - Next, a third embodiment of the present invention is described with reference to
FIG. 8 .FIG. 8 is a view showing a coolant guide mechanism in the third embodiment of the present invention. - The third embodiment shown in
FIG. 8 is substantially the same as the first embodiment shown inFIGS. 1 to 6 , excluding that the coolant guide mechanism includes a pipe passing through an upper supporting plate, with one end of the pipe being engaged with an upper header, and the other end thereof being connected to a core support. In the third embodiment shown inFIG. 8 , the same elements as those of the first embodiment shown inFIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted. - As shown in
FIG. 8 , acoolant guide mechanism 17 includes an annularupper header 18 mounted on anoutlet 14 b of anelectromagnetic pump 14, and apipe 22 passing through an upper supportingplate 29, with oneend 22 a of thepipe 22 being engaged with theupper header 18 and theother end 22 b of thepipe 22 being connected to acore support 13. Theupper header 18 is provided with downwardly projectingnozzles 19 through which a pressurizedprimary coolant 21 from theelectromagnetic pump 14 passes. The oneend 22 a of the pipe is slidably engaged with the nozzles of theupper header 18 through twoannular seals 19 a. - According to this embodiment, there is provided the
pipe 22 passing through the upper supportingplate 29, with the oneend 22 a being slidably engaged with the upper header and theother end 22 b being connected to thecore support 13. Since theoutlet 14 b of theelectromagnetic pump 14 and the upper supportingplate 29 are connected to each other through thepipe 22, theprimary coolant 21 can be guided up to alower plenum 33 without diminishing its flow rate. Thus, the efficiency of afast reactor 1 can be enhanced, as well as the sealing structure between the upper supportingplate 29 and thecore barrel 3 can be facilitated. - Next, a fourth embodiment of the present invention is described with reference to
FIG. 9 .FIG. 9 is a view showing a coolant guide mechanism in the fourth embodiment of the present invention. - The fourth embodiment shown in
FIG. 9 is substantially the same as the first embodiment shown inFIGS. 1 to 6 , excluding that an upper header includes an annular inner wall extending downwardly from an outlet of an electromagnetic pump and an annular outer wall extending downwardly from the outlet of the electromagnetic pump, and that a lower header includes an annular receiving part slidably engaged with the inner wall of the upper header and the upper wall thereof. In the fourth embodiment shown inFIG. 9 , the same elements as those of the first embodiment shown inFIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted. - As shown in
FIG. 9 , acoolant guide mechanism 17 is composed of an annularupper header 18 mounted on anoutlet 14 b of anelectromagnetic pump 14, and an annularlower header 20 disposed below theupper header 18 such that thelower header 20 is mounted on an upper supportingplate 29 so as to cover anopening 29 a of the upper supportingplate 29 from above. Theupper header 18 includes an annularinner wall 18 a extending downwardly from theoutlet 14 b of theelectromagnetic pump 14, and an annularouter wall 18 b extending downwardly from theoutlet 14 b of theelectromagnetic pump 14. In addition, formed on thelower header 20 is an annular receivingpart 20 b slidably engaged with theinner wall 18 a of theupper header 18 and theouter wall 18 b thereof. Twoannular seals 19 d are interposed between the annularinner wall 18 a and an inner side surface of the annular receivingpart 20 b. Twoannular seals 19 e are interposed between the annularouter wall 18 b and an outer side surface of the annular receivingpart 20 b. - According to this embodiment, the
upper header 18 includes the annularinner wall 18 a extending downwardly from theoutlet 14 b of theelectromagnetic pump 14, and the annularouter wall 18 b extending downwardly from theoutlet 14 b of theelectromagnetic pump 14. In addition, formed on thelower header 20 is the annular receivingpart 20 slidably engaged with theinner wall 18 a and theouter wall 18 b of theupper header 18. Since the structures of theupper header 18 and thelower header 20 can be simplified, reduction in cost can be achieved - Next, a fifth embodiment of the present invention is described with reference to
FIG. 10 .FIG. 10 is a view showing a sealing structure around an electromagnetic pump in the fifth embodiment of the present invention. - The fifth embodiment shown in
FIG. 10 is substantially the same as the first embodiment shown inFIGS. 1 to 6 , excluding that an intermediate heat exchanger and an electromagnetic pump are connected in series with each other in an up and down direction. In the fifth embodiment shown inFIG. 10 , the same elements as those of the first embodiment shown inFIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted. - As shown in
FIG. 10 , in afast reactor 1, anintermediate heat exchanger 15 and anelectromagnetic pump 14 are connected in series with each other in an up and down direction. Similarly to the first embodiment shown inFIGS. 1 to 6 , between anoutlet 14 b of theelectromagnetic pump 14 and an upper supportingplate 29, there is disposed acoolant guide mechanism 17 configured to guide a pressurizedprimary coolant 21 from theelectromagnetic pump 14 toward aneutron shield 8 through anopening 29 a of the upper supportingplate 29. Thus, it is possible to improve a sealing property between theprimary coolant 21 of a higher temperature, which has been heated by acore 2, and theprimary coolant 21 of a lower temperature, which has been pressurized by theelectromagnetic pump 14. As a result, lowering of a power generation efficiency of thefast reactor 1 can be prevented, as well as reliability of thefast reactor 1 can be enhanced. - Next, a sixth embodiment of the present invention is described with reference to
FIG. 11 .FIG. 11 is a view showing a fast reactor in the sixth embodiment of the present invention. - In the aforementioned respective embodiments, a core supporting mechanism disposed in the reactor vessel, which horizontally extends so as to support the core is formed of the upper supporting plate, and the coolant guide mechanism configured to guide the pressurized coolant from the pump for coolant is connected to the opening of the upper supporting plate, which is by way of example. However, not limited thereto, the core supporting mechanism may be formed of a core support supporting the core from below and having an opening to which a coolant guide mechanism is connected. Herebelow, a fast reactor in the sixth embodiment of the present invention is described with reference to
FIG. 11 . In the sixth embodiment shown inFIG. 11 , the same elements as those of the first embodiment shown inFIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted. - As shown in
FIG. 11 , an annularintermediate heat exchanger 15 configured to cool aprimary coolant 21 which has been heated by acore 2 is disposed between an upper supportingplate 29 and an inner surface of areactor vessel 7. As shown inFIG. 11 , an annularelectromagnetic pump 14, which is configured to pressurize the primary coolant that has passed through theintermediate heat exchanger 15 so as to be cooled, is disposed around acore 2. Theelectromagnetic pump 14 is connected in series with theintermediate heat exchanger 15 in an up and down direction. In addition, as shown inFIG. 11 , a plurality of, e.g., two annularelectromagnetic pumps 14 are connected in series with each other in the up and down direction. Due to this structure, as compared with the first to fifth embodiments, the height of thefast reactor 1 can be shortened. Thus, a material used for thereactor vessel 7 and the like of thefast reactor 1 can be reduced, whereby costs for thefast reactor 1 can be further reduced. In addition, since the height of thefast reactor 1 is shortened, thefast reactor 1 can be further stabilized, whereby a quake-resistance or the like of thefast reactor 1 can be improved. - As shown in
FIG. 11 , acore support 13 supporting thecore 2 from below is provided with anopening 13 a through which thepressurized coolant 21 from theelectromagnetic pump 14 passes. In addition, as shown inFIG. 11 , between anoutlet 14 b of theelectromagnetic pump 14 and thecore support 13, there is disposed acoolant guide mechanism 17 configured to guide a pressurizedprimary coolant 21 from theelectromagnetic pump 14 toward alower plenum 33 through the opening 13 a of thecore support 13. Thus, theprimary coolant 21 can be separated from its circumference by thecoolant guide mechanism 17, from when theprimary coolant 21 is discharged from theelectromagnetic pump 14 until when theprimary coolant 21 reaches the opening 13 a of thecore support 13. Therefore, it can be prevented that the pressurizedprimary coolant 21 of about 350° C. leaks to thehigher temperature zone 25, and that a pressure difference between the lower temperature andhigher pressure zone 24 and thehigher temperature zone 25 is applied to thelower bulkhead 6 a. As a result, lowering of a power generation efficiency of thefast reactor 1 can be prevented, as well as reliability of thefast reactor 1 can be enhanced. - In this embodiment, the configuration of the
coolant guide mechanism 17 shown inFIG. 11 is not particularly limited. For example, similarly to the first embodiment shown inFIGS. 1 to 6 , thecoolant guide mechanism 17 may be composed of an annularupper header 18 mounted on theoutlet 14 b of theelectromagnetic pump 14, and an annularlower header 20 disposed below theupper header 18 such that thelower header 20 is mounted on thecore support 13 so as to cover anopening 13 a of thecore support 13 from above. Herein, theupper header 18 may be provided with a plurality ofnozzles 19 in a circumferential direction thereof. Each of thenozzles 19 projects downward and passes therethrough the pressurizedprimary coolant 21 from theelectromagnetic pump 14. In addition, thelower header 20 may be provided with a plurality ofnozzle receivers 20 a which are slidably engaged with the correspondingnozzles 19 of theupper header 18. In this case, similarly to the second embodiment shown inFIG. 7 , therespective nozzles 19 may be connected to theupper header 18 through the spherical seating seals 19 b. - Alternatively, similarly to the fourth embodiment shown in
FIG. 9 , theupper header 18 may include the annularinner wall 18 a extending downwardly from theoutlet 14 b of theelectromagnetic pump 14, and the annularouter wall 18 b extending downwardly from theoutlet 14 b of theelectromagnetic pump 14. In addition, formed on thelower header 20 may be the annular receivingpart 20 b slidably engaged with theinner wall 18 a of theupper header 18 and theouter wall 18 b thereof. - Next, a seventh embodiment of the present invention is described with reference to
FIG. 12 .FIG. 12 is a view showing a fast reactor in the seventh embodiment of the present invention. - The seventh embodiment shown in
FIG. 12 is substantially the same as the sixth embodiment shown inFIG. 11 , excluding that a pump for coolant includes a plurality of pumps (mechanical pumps, electromagnetic pumps, etc.) disposed around a core. In the seventh embodiment shown inFIG. 12 , the same elements as those of the sixth embodiment shown inFIG. 11 are shown by the same reference numbers, and detailed description thereof is omitted. - As shown in
FIG. 12 , an annularintermediate heat exchanger 15 configured to cool aprimary coolant 21 which has been heated by acore 2 is disposed between an upper supportingplate 29 and an inner surface of areactor vessel 7. Theheat exchanger 15 is structured such that theheat exchanger 15 can be connected in series with a plurality ofelectromagnetic pumps 14 disposed around thecore 2 in an up and down direction. For example, as shown in the right side ofFIG. 12 , the oneelectromagnetic pump 14 disposed around thecore 2 is connected in series with theintermediate heat exchanger 15 in the up and down direction. In addition, as shown in the left side ofFIG. 12 , the otherelectromagnetic pump 14 may be connected in series with theintermediate heat exchanger 15 in the up and down direction. The number of theelectromagnetic pumps 14 to be disposed around thecore 2 can be suitably set depending on the specification of thefast reactor 1. - As shown in
FIG. 12 , between anoutlet 14 b of anelectromagnetic pump 14 and acore support 13, there is disposed acoolant guide mechanism 17 configured to guide a pressurizedprimary coolant 21 from theelectromagnetic pumps 14 toward alower plenum 33 through anopening 13 a of thecore support 13. Thus, theprimary coolant 21 can be separated from its circumference by thecoolant guide mechanism 17, from when theprimary coolant 21 is discharged from theelectromagnetic pumps 14 until when theprimary coolant 21 reaches the opening 13 a of thecore support 13. Therefore, it can be prevented that the pressurizedprimary coolant 21 of about 350° C. leaks to ahigher temperature zone 25, and that a pressure difference between a lower temperature andhigher pressure zone 24 and thehigher temperature zone 25 is applied to anlower bulkhead 6 a. As a result, lowering of a power generation efficiency of thefast reactor 1 can be prevented, as well as reliability of thefast reactor 1 can be enhanced. - Next, an eight embodiment is described with reference to
FIG. 13 .FIG. 13 is a fast reactor in the eight embodiment of the present invention. - The eighth embodiment shown in
FIG. 13 is substantially the same as the seventh embodiment shown inFIG. 12 , excluding that a coolant guide mechanism is connected to a lower plenum disposed on a core support. In the eighth embodiment shown inFIG. 13 , the same elements as those of the seventh embodiment shown inFIG. 12 are shown by the same reference numbers, and detailed description thereof is omitted. - As shown in
FIG. 13 , acoolant guide mechanism 17 includes anupper header 18 mounted on anoutlet 14 b of anelectromagnetic pump 14, and alower header 20 passing through anopening 13 a of acore support 13, with one end of thelower header 20 being engaged with theupper header 18 and the other end thereof being connected to alower plenum 33 of thecore support 13. Since theoutlet 14 b of theelectromagnetic pump 14 and thelower plenum 33 is connected to each other by means of thecoolant guide mechanism 17, theprimary coolant 21 can be guided up to thelower plenum 33 without diminishing its flow rate. Thus, the efficiency of afast reactor 1 can be enhanced. - Next, a ninth embodiment of the present invention is described with reference to
FIG. 14 .FIG. 14 is a fast reactor in the ninth embodiment of the present invention. - The ninth embodiment shown in
FIG. 14 is substantially the same as the first embodiment shown inFIGS. 1 to 6 , excluding that a lower header is formed of a nozzle receiver disposed on an upper supporting plate. In the ninth embodiment shown inFIG. 14 , the same elements as those of the first embodiment shown inFIGS. 1 to 6 are shown by the same reference numbers, and detailed description thereof is omitted. - As shown in
FIG. 14 , acoolant guide mechanism 17 includes an annularupper header 18 mounted on anoutlet 14 b of anelectromagnetic pump 14, and an annularlower header 20 disposed below theupper header 18 and is mounted on an upper supportingplate 29. As shown inFIG. 14 , theupper header 18 is provided with a plurality ofnozzles 19 in a circumferential direction thereof. Each of thenozzles 19 projects downward and passes therethrough a pressurizedprimary coolant 21 from theelectromagnetic pump 14. As shown inFIG. 14 , thelower header 20 is formed of a plurality of nozzle receivers 27 slidably engaged with thenozzles 19 of theupper header 18. Anannular seal 19 a is interposed between thenozzles 19 and the nozzle receivers 27. - As shown in
FIG. 14 , each of the nozzle receivers 27 includes a receivingpart 27 b slidably engaged with thenozzle 19 of theupper header 18, and atapered receiving base 27 a configured to guide the correspondingnozzle 19 of theupper header 18 to the receivingpart 27 b. As shown inFIG. 14 , the nozzle receiver 27 is fixed on the upper supportingplate 29 by means of a clamp 27 c. In addition, as shown inFIG. 14 , a sealingmember 51 is interposed between the nozzle receiver 27 and the upper supportingplate 29. With the use of this structure, the structure of thelower header 20 can be more simplified, whereby reduction in cost can be achieved. - In this embodiment, the
lower header 20 formed of the nozzle receivers 27 is fixed on the upper supportingplate 29, which is by way of example. However, not limited thereto, thelower header 20 formed of the nozzle receivers 27 may be fixed on acore support 13. Namely, in the embodiments (aforementioned third and sixth to eighth embodiments) in which thecoolant guide mechanism 17 is connected to thecore support 13, thelower header 20 formed of the nozzle receivers 27 may be used.
Claims (16)
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JP2009107950 | 2009-04-27 | ||
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Also Published As
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CA2759865C (en) | 2015-11-24 |
CA2759865A1 (en) | 2010-11-04 |
CN102414757A (en) | 2012-04-11 |
EP2426670A4 (en) | 2013-12-18 |
RU2011148238A (en) | 2013-06-10 |
JP2010276602A (en) | 2010-12-09 |
WO2010126028A1 (en) | 2010-11-04 |
RU2503071C2 (en) | 2013-12-27 |
US9093182B2 (en) | 2015-07-28 |
EP2426670A1 (en) | 2012-03-07 |
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